CN111451496A

CN111451496A - Metal powder tablet press die capable of preventing die clamping and facilitating die stripping

Info

Publication number: CN111451496A
Application number: CN202010281100.1A
Authority: CN
Inventors: 卢祺; 黄锋
Original assignee: Wuhan University of Technology WUT
Current assignee: Wuhan University of Technology WUT
Priority date: 2020-04-10
Filing date: 2020-04-10
Publication date: 2020-07-28
Anticipated expiration: 2040-04-10
Also published as: CN111451496B

Abstract

The invention discloses a metal powder tablet press die capable of preventing die clamping and facilitating demolding, which comprises a die pad at the bottom, wherein a hollow female die is sleeved on the die pad, and a punch is inserted into the center of the female die; the punch consists of a punch cap section and a punch press rod, and the bottom surface of the punch press rod is provided with a sticker; the punch press rod is inserted into the filling hole. According to the invention, through the design of the structure and the size of each component, the metal scraps on the inner wall of the female die can be effectively cleaned, the descending direction of the punch is controlled, and the parison and the punch are isolated, so that the problems of die clamping and difficult demoulding of the existing die for a metal powder tablet press are solved.

Description

Metal powder tablet press die capable of preventing die clamping and facilitating die stripping

Technical Field

The invention relates to the field of powder metallurgy, in particular to a metal powder tablet press die capable of preventing die clamping and facilitating demolding.

Background

Powder metallurgy is a process technique for producing metal powder or metal powder (or a mixture of metal powder and nonmetal powder) as a raw material, and then forming and sintering the raw material to produce metal materials, composite materials and various products.

Powder metallurgy includes milling and articles. The basic flow of the powder metallurgy process comprises powder preparation, powder mixing, forming, sintering and post-treatment. Wherein the forming is a process of filling the uniformly mixed material into a compression mold to be pressed into a parison with certain shape, size and density.

The forming method is basically divided into press forming and pressureless forming. Press forming is most widely used in press forming. In the process of using a tablet press die to press and form the alloy powder, metal powder can form metal scraps on the inner wall of the die, the metal scraps are accumulated to cause die clamping, and if the size design of each component of the die is unreasonable, the die clamping can be caused. In addition, if the pressure is applied to it, the parison sticks to the punch and makes demolding difficult. The clamping and demoulding difficulties can greatly reduce the working efficiency of experimenters, and even can lead to the mould not to be used in severe cases.

Disclosure of Invention

Aiming at the problems of the existing metal powder tablet press mold, the invention aims to provide the metal powder tablet press mold which can prevent the mold from being blocked and is beneficial to demolding, and the metal powder tablet press mold can effectively prevent the mold from being blocked and is beneficial to taking out a parison from the mold.

In order to achieve the purpose, the invention designs a metal powder tablet press die which prevents die clamping and is beneficial to demoulding, comprising a die pad at the bottom, wherein a hollow female die is sleeved on the die pad, and a punch is inserted into the center of the female die; the punch consists of a punch cap section and a punch press rod, and a sticker (used for separating the punch from the parison) is arranged on the bottom surface of the punch press rod; the punch press rod is inserted into the filling hole.

Furthermore, the punch press rod is divided into three sections, namely an upper section of the press rod, a middle section of the press rod and a lower section of the press rod; knurling is processed in the circumferential direction of the outer surface of the middle section of the pressure lever.

And furthermore, the diameter of the middle section of the pressure rod is equal to the diameter of the lower section of the pressure rod, the difference between the diameters of the middle section and the lower section of the pressure rod and the diameter of the target parison is 2-3 times of the diameter of the metal powder, the diameter of the upper section of the pressure rod is smaller than the diameter of the middle section of the pressure rod, the length of the upper section of the pressure rod is twice of the length of the middle section of the pressure rod, and the length of the.

Furthermore, the filler hole is divided into an upper section and a lower section, namely an upper section and a lower section; the diameter of the lower section of the filling hole is the diameter of the target parison; the diameter of the upper section of the filling hole is larger than that of the lower section of the filling hole, the depth of the lower section of the filling hole is the maximum thickness of the parison, the depth of the upper section of the filling hole is twice that of the lower section of the filling hole, and the length of the punch press rod is larger than that of the filling hole of the female die.

Still further, the diameter of the demoulding hole is larger than that of the filling hole.

And the die pad is composed of three cylinders, the upper die pad section, the middle die pad section and the lower die pad section are respectively arranged, the middle die pad section is inserted into the demolding hole, the upper die pad section is inserted into the lower filling hole section, the diameter of the lower die pad section is larger than that of the middle die pad section, the diameter of the middle die pad section is smaller than that of the demolding hole of the female die, the length of the middle die pad section is larger than that of the demolding hole of the female die, and the diameter of the upper die pad section is equal to that of the lower pressing rod section.

Before tabletting, the paster is pasted on the end surface of the lower section of the pressure rod, the female die demoulding hole is downwards sleeved on the die pad, and the upper section of the die pad can extend into the female die filling hole to prevent metal powder from leaking into the female die demoulding hole due to the fact that the length of the middle section of the die pad is larger than that of the female die demoulding hole. And filling metal powder into the female die filling hole, shaking the die until the upper surface of the powder is flat, filling the punch press rod into the female die filling hole, and putting the whole die into a tablet press for tabletting. And after the tabletting is finished, the die is taken down from the tablet press, the die cushion is taken down, then the die is put into the tablet press again for demoulding, the punch press rod is longer than the depth of the filling hole of the female die, the press rod can push the parison formed after the metal powder is pressed out of the filling hole after the punch is pressed, and the parison is easily separated from the press rod because the paster is arranged between the parison and the press rod. Because the depth of the upper section of the filling hole of the female die is twice of the depth of the lower section of the filling hole, and the thickness of the parison to be pressed is not larger than the depth of the lower section of the filling hole of the female die, the stroke of the punch press rod in the female die is limited in the tabletting process, the punch cannot incline in the descending process, and the punch cannot be clamped in the female die. Because the knurling is processed at the middle section of the punch press rod, the metal chips bonded on the inner wall of the filling hole of the female die can be removed by utilizing the knurling, and the punch press rod can be prevented from being clamped in the female die due to accumulation of the metal chips. Because the difference between the diameters of the middle section and the lower section of the pressure rod and the diameter of the target parison is two to three times of the diameter of the metal powder particles to be formed, a punch is not clamped in a female die due to the fact that the gap between the middle section and the lower section of the pressure rod and a filling hole of the female die is too small in the tabletting process, and an excessively obvious flange is not formed on the upper surface of the parison due to the fact that the gap is too large. The diameter of the upper section of the punch press rod is smaller than that of the middle section of the press rod, and the diameter of the upper section of the filling hole of the female die is larger than that of the lower section of the filling hole, so that the punch can be conveniently withdrawn from the female die.

The invention has the beneficial effects that:

1. according to the metal powder tablet press die, when the die is demolded, the punch press rod pushes the parison into the demolding hole from the die filling hole due to the fact that the length of the punch press rod is larger than the depth of the die filling hole, and the parison is taken out conveniently.

2. The die of the metal powder tablet press is beneficial to separating the parison from the punch press rod because the punch press rod and the parison are separated by the sticker when demoulding.

3. According to the metal powder tablet press die, knurling is processed on the middle section of the punch press rod, metal chips adhered to the inner wall of the filling hole of the female die can be removed through knurling, and the punch press rod can be prevented from being clamped in the female die due to accumulation of the metal chips.

4. According to the metal powder tablet press die, because the depth of the upper section of the filling hole of the female die is twice of the depth of the lower section of the filling hole, and the thickness of a parison to be pressed is not larger than the depth of the lower section of the filling hole of the female die, the stroke of the punch press rod in the female die is limited in the tablet pressing process, the punch cannot incline in the descending process, and the punch cannot be clamped in the female die.

5. According to the metal powder tablet press die, because the difference between the diameters of the middle section and the lower section of the compression rod and the diameter of the target parison is two to three times of the diameter of metal powder particles to be formed, the compression rod cannot be clamped in the concave die due to too small gaps between the middle section and the lower section of the compression rod and the filling hole of the concave die in the tablet pressing process, and an excessively obvious flange cannot be formed on the upper surface of the parison due to too large gaps.

6. According to the die of the metal powder tablet press, the length of the middle section of the die pad is larger than that of the die release hole of the female die, so that the upper section of the die pad can extend into the filling hole of the female die, and metal powder is prevented from leaking into the die release hole of the female die.

7. According to the die of the metal powder tablet press, the diameter of the upper section of the punch press rod is smaller than that of the middle section of the press rod, and the diameter of the upper section of the filling hole of the female die is larger than that of the lower section of the filling hole, so that the punch can be conveniently withdrawn from the female die.

Drawings

FIG. 1 is a schematic view of the structure of a die of a metal powder tablet press;

FIG. 2 is an exploded view of the punch and decal;

FIG. 3 is view A of FIG. 2;

FIG. 4 is a schematic structural view of a female mold;

FIG. 5 is view B of FIG. 4;

FIG. 6 is a schematic view of the die pad;

FIG. 7 is view C of FIG. 6;

FIG. 8 is a schematic view of a metal powder tablet press die assembly parison;

FIG. 9 is a schematic view of a preform made by a metal powder tablet press die;

FIG. 10 is a schematic view of metal shavings scraped off the inner wall of the female die;

in the figure, a die cushion 1, a die cushion upper section 1.1, a die cushion middle section 1.2, a die cushion lower section 1.3, a female die 2, a filling hole 2.1, a filling hole upper section 2.11, a filling hole lower section 2.12, a demoulding hole 2.2, a punch 3, a punch cap section 3.1, a punch press rod 3.2, a press rod upper section 3.21, a press rod middle section 3.22, a press rod lower section 3.23, a paster 4, a knurl 5 and a parison 6.

Detailed Description

The present invention is described in further detail below with reference to specific examples so as to be understood by those skilled in the art.

The die of the metal powder tablet press which is used for preventing die clamping and is beneficial to demoulding as shown in figures 1-7 is used for pressing 4g of uniformly mixed magnesium powder and nickel powder with the granularity of 300 meshes into a parison 6 with the granularity of about 8mm, and comprises a die pad 1 at the bottom, wherein the die pad 1 consists of three sections of cylinders, the upper section 1.1 of the die pad, the middle section 1.2 of the die pad and the lower section 1.3 of the die pad are respectively arranged,

the diameter of the lower section 1.3 of the die pad is 45mm, and the length of the lower section 1.3 of the die pad is 10 mm; the diameter of the 1.2 middle section of the die cushion is 24.96mm, and the length of the 1.2 middle section of the die cushion is 15 mm; the diameter of the upper section 1.1 of the die pad is 14.88mm, and the length of the upper section 1.1 of the die pad is 3.5mm.

A hollow female die 2 is sleeved on the die pad 1, a through hole is formed in the center of the female die 2 and comprises a filling hole 2.1 in the upper part and a demoulding hole 2.2 in the lower part, and the middle section 1.2 of the die pad is inserted into the demoulding hole 2.2;

the filling hole 2.1 is divided into an upper section and a lower section, namely an upper section 2.11 of the filling hole and a lower section 2.12 of the filling hole;

the upper section 1.1 of the die pad is inserted into the lower section 2.12 of the filling hole, the diameter of the upper section 2.11 of the filling hole is 15.16mm, the depth of the upper section 2.11 of the filling hole is 20mm, the diameter of the lower section 2.12 of the filling hole is 15mm, and the depth of the lower section 2.12 of the filling hole is 10 mm; the diameter of the demoulding hole 2.2 is 25.1mm, the depth of the demoulding hole 2.2 is 15mm, the diameter of the outer surface of the female die 2 is 45mm, and the length is 45 mm.

A punch 3 is inserted into the center of the female die 2; the punch 3 consists of a punch cap section 3.1 and a punch press rod 3.2, and the punch press rod 3.2 is inserted into the filler hole 2.1;

the bottom surface of the punch press rod 3.2 is provided with a paster 4 with the diameter of 14.88mm for separating the punch from the parison 6;

the punch press rod 3.2 is divided into three sections, namely an upper section 3.21 of the press rod, a middle section 3.22 of the press rod and a lower section 3.23 of the press rod; knurling 5 is processed on the outer surface of the middle section 3.22 of the pressure lever in the circumferential direction.

The diameter of the middle section 3.22 of the pressure rod is equal to that of the lower section 3.23 of the pressure rod and is 14.88mm, the difference between the diameter of the middle section 3.22 and the diameter of the lower section 3.23 of the pressure rod and the diameter of the target parison 6 is 2-3 times of the diameter of the metal powder, and the diameter of the upper section 3.21 of the pressure rod is 14.6 mm; the lengths of the upper section 3.21 of the pressure lever, the middle section 3.22 of the pressure lever and the lower section 3.23 of the pressure lever are respectively 20mm, 10mm and 2 mm.

As shown in fig. 8: before tabletting, the paster 4 is attached to the end face of the lower section 3.23 of the punch press rod, the female die demoulding hole 2.2 faces downwards and is sleeved on the die pad 1, metal powder is filled into the filling hole 2.1 of the female die 2, the die is shaken until the upper surface of the powder is smooth, the punch press rod 3.2 is filled into the filling hole 2.1 of the female die 2, and the whole die is put into a tabletting machine for tabletting. And taking the die from the tablet press after the tabletting is finished, taking the die pad 1 off, putting the die into the tablet press again for demoulding, cleaning the metal chips on the inner wall of the filling hole of the female die by utilizing the knurl of the middle section 3.22 of the compression bar after the demoulding is finished, tabletting for the next time, and removing the heavy paster if the paster 4 is damaged in use.

As shown in fig. 9: the diameter of the parison 6 prepared in this example is 15mm, and since the depth of the lower section 2.12 of the filling hole of the die 2 is 10mm, the thickness of the target parison 6 should not be more than 10mm, and the thickness of the parison 6 prepared in this example is 8 mm. The diameter of the lower section 2.12 of the filling hole is 0.12mm larger than that of the middle section 3.22 of the compression rod and the lower section 3.23 of the compression rod, the filling in the embodiment is 300-mesh magnesium powder and 300-mesh nickel powder which are uniformly mixed, no obvious blockage occurs in the process of tabletting and punch withdrawing, and no obvious flange exists on the edge of the upper surface of the prepared parison 6. Because the middle section 3.22 of the punch press rod is provided with the knurls, the knurls can be used for clearing metal chips (figure 10) adhered to the inner wall of the filling hole 2.1 of the female die 2, and the punch press rod 3.2 can be prevented from being clamped in the female die 2 due to accumulation of the metal chips.

Because the length of the middle section 1.2 of the die pad is larger than the length of the demoulding hole 2.2 of the female die, the upper section 1.1 of the die pad can extend into the filling hole 2. the inner part 1 of the female die 2, and the metal powder filled into the female die 2 can not leak into the demoulding hole 2.2 of the female die 2.

During demoulding, because the total length of the punch press rod 3.2 is greater than the total depth of the filling hole 2.1 of the female die 2, the punch press rod 3.2 can push the parison 6 into the demoulding hole 2.2 from the filling hole 2.1 of the female die 2, and the parison 6 can be taken out conveniently. The separation of the parison 6 from the punch press rod 3.2 is facilitated by the sticker 4 between the punch press rod 3.2 and the parison 6.

Because the depth of the upper section 2.11 of the filling hole of the female die 2 is twice of the depth of the lower section 2.12 of the filling hole, and the thickness of the parison 6 to be pressed is not more than 10mm, the stroke of the punch press rod 3.2 in the female die 2 is limited in the tabletting process, the punch 3 cannot be inclined in the descending process, and the punch 3 cannot be clamped in the female die 2.

Because the clearance between the upper section 2 of the pressure lever and the upper section 2.11 of the filling hole is smaller than the clearance between the middle section 3.22 of the pressure lever and the lower section 3.23 of the pressure lever and the lower section 2.12 of the filling hole, the punch 3 can be conveniently withdrawn from the female die 2.

Other parts not described in detail are prior art. Although the present invention has been described in detail with reference to the above embodiments, it is only a part of the embodiments of the present invention, not all of the embodiments, and other embodiments can be obtained without inventive step according to the embodiments, and the embodiments are within the scope of the present invention.

Claims

1. A metal powder tablet press die capable of preventing die clamping and facilitating demolding comprises a die pad (1) at the bottom, wherein a hollow female die (2) is sleeved on the die pad (1), and a punch (3) is inserted into the center of the female die (2); the method is characterized in that: the punch (3) consists of a punch cap section (3.1) and a punch press rod (3.2), and a sticker (4) is arranged on the bottom surface of the punch press rod (3.2); the punch press is characterized in that a through hole is formed in the center of the female die (2), the through hole comprises an upper filling hole (2.1) and a lower demolding hole (2.2), and the punch press rod (3.2) is inserted into the filling hole (2.1).

2. The metal powder tablet press die of claim 1, which prevents sticking and facilitates die release, wherein: the punch press rod (3.2) is divided into three sections, namely an upper press rod section (3.21), a middle press rod section (3.22) and a lower press rod section (3.23); knurling (5) is processed on the outer surface of the middle section (3.22) of the pressure lever in the circumferential direction.

3. The metal powder tablet press die of claim 2, which prevents sticking and facilitates die release, wherein: the diameter of the middle section (3.22) of the pressure lever is equal to the diameter of the lower section (3.23) of the pressure lever, the difference between the diameter of the middle section (3.22) of the pressure lever and the diameter of the lower section (3.23) of the pressure lever and the diameter of the target parison is 2-3 times of the diameter of the metal powder, the diameter of the upper section (3.21) of the pressure lever is smaller than the diameter of the middle section (3.22) of the pressure lever, the length of the upper section (3.21) of the pressure lever is twice of the length of the middle section (3.22) of the pressure lever, and the length of the lower section.

4. The metal powder tablet press die of claim 1, which prevents sticking and facilitates die release, wherein: the packing hole (2.1) is divided into an upper section and a lower section, namely an upper section (2.11) and a lower section (2.12) of the packing hole; the diameter of the lower section (2.12) of the filling hole is the diameter of the target parison; the diameter of the upper section (2.11) of the filling hole is larger than that of the lower section (2.12) of the filling hole, the depth of the lower section (2.12) of the filling hole is the maximum parison thickness capable of being pressed, the depth of the upper section (2.11) of the filling hole is twice of that of the lower section (2.12) of the filling hole, and the length of the punch press rod (3.2) is larger than that of the filling hole (2.1) of the female die.

5. The metal powder tablet press die for preventing sticking and facilitating die release according to claim 1 or 4, wherein: the diameter of the demoulding hole (2.2) is larger than that of the filling hole (2.1).

6. The metal powder tablet press die of claim 2, which prevents sticking and facilitates die release, wherein: the die cushion (1) is composed of three cylinders, and is respectively provided with a die cushion upper section (1.1), a die cushion middle section (1.2) and a die cushion lower section (1.3), wherein the die cushion middle section (1.2) is inserted into a demoulding hole (2.2), the die cushion upper section (1.1) is inserted into a filling hole lower section (2.12), the diameter of the die cushion lower section (1.3) is larger than that of the die cushion middle section (1.2), the diameter of the die cushion middle section (1.2) is smaller than that of a female die demoulding hole (2.2), the length of the die cushion middle section (1.2) is larger than that of the female die demoulding hole (2.2), and the diameter of the die cushion upper section (1.1) is equal to that of the lower section (3.23).